Stop-valve



Patented Ian. |0,. 1899L H.- cocHRAN.v STOP VALVE. {Applimion med Nov.19, 1897.)

(No Model.)

umbmn w/rNEssEs f.,-

.my invention.

UNITED STATES PATENT OFFICE.

iiEYw-ooD COCHRAN, vor` JoHNsioWN, PENNSYLVANIA.

sPEemicaTioNromng-paa er aettersratent'iv..617,437, dated January 1o,ieee." f

'fifeiicaaitieamember19,1867. 'sei-mia. eseguiti' canarini" ToaZZ-whon/z/Hitmay concern/: i i

Beit known that I, HEYWOOD ful Improvements `in Stop -Valves', ofwhichthe followingspecication isa tr and exact description, due referencebeing had to the aocompanyin g drawings. Y

My invention specially relates to that yclass of valves used in a pipesystem to cut o andl close one portion of the system from therest.

The object of valve having certain new and useful features, as will behereinafter described and claimed. While the valve embodying myinventionmaybe employed in a variety of ways and-in systems. for thevdistribution of water, gas, steam, or like uses, ployed in arefrigerating system.

Referring-mths drawings, Figurel represcnts a sectional view of a,valvevembodying Fig. 2 is a. diagrammatic View of an ice-making pla'nt,showing a valve constructed in accordance with my invention and thepiping accompanying the saine. In Fig. 2, A is the cylinderof thegas-compressor, and B the piston in thesaine. y C-is the discharge-pipefrom the compressor, leading to valve D, which valve embodies myinvention. From this' valve D leads the condenser-coil E in tank F.-From the bottom of coil E is the liquid-pipe G for `supplyingrefrigerating-coil H through regulating-valve I. The coil H is submergedin the brine-tank K, in which areplaced the ice-cans L in the usualmanner. Theother end-.of coil H is connected, through pipe M, to thesuction side of conipressor A. This is the customary manner of arranginga plant of this kind.

'When the compressor Ais stopped for'any length of time, it is customarytoclosethe valves D and I in ordei` to bottle'up the highpressure liquidand gas in the condenser-coil E to prevent any possible loss throughleaks in the rest of the system. Usually valve ID is the regularplug-valve closed by screwing the stem down upon; the seat, and thiswhen closed is absolutely fixed in its position, and, moreover, it mustbe operated by hand, to do which the operator inust vgo to it be itwhere it may. Should the compressor start up when tlis valve was closedthrough oversight, it

e, would compress. .the gas l COCHRAN; of., Johnstown, county ofCambria, State of Penn- Sylvania, have invented certain new and usemyinvention is to provide av I will describe it as em-I This pocket maycharge-pipe 0,in whichcons'equently the pres- 'sre would rapidly riseuntileither the :pipe

and an accident more or or compressor failed lessl serious would result.

j lTo 'provide a valve which may be. operated froma distance and alsoinsures against a dangerous pressure in the system should the compressorbe started while the valve is closed is the object of my invention.A

.Referringto Fig. l, N is the body ofxthe valve, C the connection to thedischarge-pipe c from the compressor, and e the connection tothe'condenser-coil E.' f

rinto the small disn WithinV the body N and adapted .to reciprocate inthe suitably-formed chamber O is the piston gage the-mouth of connectionand bywithdrawing :open it. stem-I has -ineii''ect twojpistons formedupon e and close it it, the one, p', of one diameter, and the other, Y'

valve-stem P,which is adapted to en lThis lvalve- 2, of greaterdiameter, each-fitting-a portion of the chamber O of the-samediameterand suitably packed against the leakage of gas by the packings R ofthechamber O between the pistons is 'open through vent Q in to thesurrounding pocketS; be kept iilled with water, oil, glycerin, or anysuitable liquid, through which any gas passing either of the pistonsmust find its way and be apparent by the bubbles it causes. the chamber0, and in it maybe found the cavity O', adapted to receive the stud p3on stem P and act as a dash-pot to check the mo- The plugT closes theend ofV The intermediate portion 1 tion of the stem P. Into the spaceabove the e large piston p2 lead the ducts U and V. These in Fig. 2 inturn are connected` with the highpressure-liquid pipe and thelow-pressure return-pipe M through plain stop-valves u and fu.

'The manner of operating the valve D is as follows: To close it, thevalve u isopened, thereby admitting the hig -pressure gas into thatinthe discharge-pipe @acting upon pis'- .95 chamber O, so as to actuponpiston p2, and

1 cpo sure to fall. lThe areas of the two pistons may be so proportionedas to open the valve at any predeton p', is sufficient t-vercome theloxvpressure upon piston p2, and therefore the valve is raised and opened.The areas of the two pistons should be so proportioned tothe workingpressure that this result will be obtained. Now should the compressorfor any reason be started while' the high-pressure valve udwas open andthe valve 4consequently down, the result would be that the pressurewould at once rise in pipec, as was the case when the usual hand-valvewas employed. Instead,

however, of increasing until something failed,

it would only rise to that point where it balanced the pressure uponpiston p2. Any further increase would open the valve and allow the gasto Iiow into condenser E and the prestermined rise of pressure in pipe cover that in the condenser.

While I have shown the low-pressure pipe V as returning the gas to thesuction side of the system, it will be understood that this is done forthe purpose of saving the gas in the pipe V, which would votherwise bewasted. Were the valve used on a system I for steam, air, or otheragentwhere this saving would not be considered, the two valves 'wand fumight be combined into one three-way valve pressure beneath may beclosed. In the case .of an ammonia refrigerating plant this is avaluablefeature, as it sometimeshappens in thecase of a break in the pipes thatthe .wholecharge of ammo nia escapes on account of the stop-valves beingso placed as to be nnapproachable on account of the gas-fumes.

In the' claims I llave, for convenience, considered the chamber O as twochambers, one for each piston; but it will be understood that they maybe combined, as shown.

Having thus described my invention, what I claim, and desire to protectby Letters Patent, is v 1.- A pipe-valve comprisinga body, acham ber insaid body'a'ndrin connection with theV inlet and outlet orifices of thevalve, a piston in said chamber and having a valve-stem adapted to closethe outlet-oriiice, the piston being so arranged that the pressure'fromthe inlet is constantly exerted upon it to open the valve, a secondpiston of .larg-br area'than the fnvstand in a second chamber, means foradmitting pressure from the system upon the last-mentioned piston-tocause it to 'close the valve and means for varying the pressure.

2. In a valve, in combination with the body, a pair of chambers therein,one of greater area than the other, a pair of connected pistons eachiitting one of the chambers and adapted to reciprocate therein, a.valve-stemV operated by said pistons, means for applying of the pistonsand means for applying a variable pressure to the other.l i

In testimony whereof Ihave affixed my signature in presence of twowitnesses.

HEYWOOD,"COCIIRAN. Witnesses: i i' a i WARD RAYMOND,

DANL. W. PATTERSON.

a constant pressure from the system'to one '4

